Mechanical pencil



Patented Feb. 8, 1949 UNITED STATES PATENT GFFICE 2,461,408 A MECHANICAL PENCIL Ray Brosseau, Kew Gardens, N. Y. Appia-.men August '16, 194e, serial No. 69u52 This invention relates to .mechanical pencils and more particularly to pencils in which the writing element is mechanically advanced to Writing position,

The principal object of this invention is the provision of a mechanical pencil in which a precision type of positive acting mechanism is em' ployed to advance the writing element to writing position as well asto supply successive writing elements and to bring them into writing position.

Another object of this invention is the provi- .sion of a mechanical pencil in which the mecha.- nism for advancing the writing element performs a 'second function which .is that oi gripping and holding the writing element in writl ing position and preventingsaid writing element from wobbling or becoming displaced.

A further object of this invention is the .provision of a mechanical pencil in which the mechanism for advancing the Vwriting element is adapted automatically to advance said writing element a predetermined distance. `This and other objects are attained by the mechanism .i1- iustrated in the accompanying drawing in which- Fig. 1 is a side elevational view of a mechanical pencil embodying the feed and holding mechanism herein claimed, the casing of said pencil being partly broken away to expose said mechanism;

Fig. 2 is a fragmentary vertical section through said pencil and through the feed and holding mechanism thereof, said mechanism being 'shown holding the writing element in writing position;

Fig. 3 is a view similar to that of Fig. 2 showf i ing the `i'lrst stage in the feeding operation, .this stage being solely that of holding the writing element to prevent its longitudinal movement and bring the feeding element into operative position;

Fig. 4 is a View similar to that of Fig. 3 showing a more advanced stage in the operation, this view showing the feeding mechanism about to be placed into operative position; and

Fig. 5 is a view similar to that of Fig. 4 showing the feeding mechanism in operative position and advancing or feeding the'writing element.

Referring to Fig. 1 it will be seen that the mechanical pencil i9 .herein claimed is provided with a casing or barrel il, a pocket clip l2, an eraser 'I3 at 'the upper end of the casing anda writing element or lead ifiA extending through a hole in the lower end of the casing. The barrel li may be made in two sections as shown in Fig. 1, to wit, the upper section and a lower sec-r 2 Claims. (Cl. 1Z0-17) 2r v i tion aixed together in any conventional manner. This type of construction will facilitate introduction of the feeding and holding mechanism hereinafter described into the barrel. It will .also be noted that an opening or slot i5 is provided in the .side of the barrel. rating a slot into the barrel `will shortly Vbecome apparent.

Referring now to Figs. 2 to 5 inclusive, it rwill be seen that the lowerporticn ila oi the barrel is a relatively Solid mass having a tubular opening .extending longitudinally therethroughto accommode-te the writing element it. Above portion 'Ha is a hollow chamber 20- and above said hollow `chamber is the upper portion lb ci 'the casing H, this upper portion comprising also relatively solid construction. Extending longi tudinally through the center of upper portion l ib is a vtube 2l, said tube 4extending downwardly rin part into the cavity or chamber 28. AThis tube is a magazine for the writing element it and more particularly for a plurality of said elements arranged in line one following the other as shown :in Asaid Figs. 2 to 5 inclusive. The-writing elements feed through the magazine 2l and as one of .said elements is consumed it is followed lby another element which takes its place. The dimensions of the magazine 2| are such that the 'writing elements lil are slidably mounted therein so that `when the pencil is held vertically there is fa tendency for these writing elements to move downwardly through and out of said magazine.

This may be designated as a gravity feed,

y Slidably mounted on the downwardly extending end of magazine 2i is a chuck 25. It will be noted that this chuck is provided with a rather large .head 26 and a bifurcated shank '2l which is smaller at the top and larger at the bottom. The lower ends of the bifurcated shank 21 carry the gripping portions or shoes 2S. Normally the 'lower ends of said bifurcated shank aresprung outwardly as shown in Fig.- 4 so that the gripping portions 28 are normally out of contact with the writing elementfl. Y

At the lower end of the chamber 20 is a second chuck 30. vUnlike the rst chuck`25 which is lon gitudinallymovable on the magazine tube 2 I, this second chuck '.30 is fixed at 3| in a recess formed in the lower solid portion l lot` ofl the barrel il. This chuck 30 is also -provided with a bifurcated shank 32 and gripping portions or shoes 3.3k are formed lon the upper endsoi"` said bifurcated shank. Unlike the shank of chuck 25, the lower end of the shank of chuck 30 is smaller than its upper end. The normal condition of chuck 30 is The reason' for incorpoits open position shown in Fig. 2, its bifurcated shank being normally sprung outwardly. In such position its gripping portions are out of Contact with the Writing member I4.

Mounted on the shank of chuck is a collar 40 and mounted on the shank of chuck 39 is a second collar 4|, these two collars being joined by means of a yoke 42 with which they are integral. It will be noted that a portion 43 of said yoke extends through the opening I5 in the side wall of the barrel I I. It will also be noted that a plate 44 on the outside of said barrel is affixed to upwardly extending portion 43.

Plate 44 is a finger member by which the collars 40 and 4I may simultaneously be moved in a longitudinal direction, either upwardly or downwardly as the case may be. The normal position of the finger member 44 is shown in Fig. 2. This is its lowermost position. When the iinger member 44 is in this position, the yoke 42 and the collars 40 and 4i are also at their lowermost positions. The collar 4I is at the smaller end of the chuck and it is therefore out of engagement with said chuck in the sense that it does not squeeze the two gripping ends of the chuck together. The collar 4G on the other` hand is somewhere below the small end of the bifurcated shank 21 of the chuck 25. It is in engagement with said chuck therefore in the sense that it squeezes the two gripping ends oi the chuck to gether so that they in turn are in tight engagement with the writing element I4. This is shown in-Fig. 2.

j QWhen the writing element I4 is worn down and it is desired to advance it, the nger member 44 is pushed upwardly through the position shown in Fig. 3, to the position shown in Fig. 4. As it is thus moved upwardly the collar 4l is brought into engagement with the thicker end of the chuck 30 and it thereby closes said chuck upon writing element I4. This is shown in Figs. 3 and 4. At the same time collar moves upwardly and it disengages the thicker end of the chuck 25 thereby opening said chuck, it also engages the head 26 of said chuck and pushes the chuck up through the position shown in Fig. 3 to the position shown in Fig. 4. It will be seen that this operation causes chuck 25 to release the writing element I4 but no longitudinal movement of said writing element is thereby permitted for thereason that simul taneously therewith the gripping operation of chuck 34 takes place.

The nger member 44 is now-pushed downwardly as shown in Fig. 5. There is no immediate contact made between the collar 40 and the larger lower end of chuck 25. Instead said chuck moves downwardly with the collar 40' simply-by virtue of the attraction of gravity upon it. But this free Vdownward movement of chuck 25 is negligible and such movement is arrested by the stop portion which extends inwardly into the chamber 20 from the inner wall of the barrel II. The lower end of the chuck 25 being sprung outwardly engages said stop portion 50 and further free downward movement of said chuck is prevented. The collar 40 however continues to move downwardly with the linger member 44. As it does so it engages the larger lower end of the chuck 25 and squeezes said end together. .This has the eiect of causing said chuck to grip writing element I4 and at thesame time it frees said chuck from the holding action of the stop portion 50. The chuck 25 now moves downwardly with the iinger member 44. At the same time a corresponding downward movement of the collar 40 is caused. This results in opening the lower chuck 3i) and thereby causing said chuck to release the writing element I4. Since the upper chuck 25 now engages the writing element, further movement downwardly oi said upper chuck 25 will cause a corresponding movement of the writing element I4. When the iinger member 44 reaches its lowermost position as shown in Fig. 2, the writing element has been advanced as deslred.

It will be understood from the foregoing that only a preferred embodiment of the invention has been shown and described. Modifications may be incorporated therein Without departure from the spirit of the invention.

- What has above been described is a positiveaction mechanism for mechanical pencils. There are no springs to become loose or to get out of order in the many ways that are common to conventional mechanical pencils. The gripping action on the writing element is sure and the force exerted upon the writing element is equal on all sides thereof. There is, therefore, no unbalanced force which might tend to break the writing element before it leaves the pencil. As a matter of iact, said writing element is protected against breaking even after it leaves the casing of the pencil and when it is in actual writing position. It will be noted in Fig. 1 that the lowermost end of the casing is longer on one side than it is on the other, and that it tapers upwardly from said longer side to the shorter side. The longer end comprises a lip EB which is adapted to serve as a guard or backrest for thewriting element to prevent it from breaking during the writing operation. The shorter end provides considerable clearness for writing purposes.

1. In a mechanical pencil a feeding mechanism for the writing element, said feeding mechanism comprising a iixed chuck and a movable chuck, a collar for each of said chucks adapted to close and open said chucks, a yoke connecting said collars and a finger member connected to said yoke whereby said yoke and the Vcollars connected thereto may be longitudinally moved to cause upward movement of the movable chuck and at the same time causing said movable chuck to open and said xed chuck to close and then downward movement of the movable chuck and at the same time causing said movable chuck to close and said fixed chuck to open.

2. In a mechanical pencil in accordance with claim 1, a stop member to engage the movable chuck to prevent its downward movement until the collar of said chuck engages and closes said chuck.

RAY BROSSEAU.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS 2,385,442 Hoffman Sept. 25, 1945 

